1. Field of the Invention
The present invention relates to a two-way communication method in which data can be transmitted and received between a transmitter attached to a moving patient and a central monitor receiver, more particularly, relates to a two-way application protocol algorithm in which, a position of a mobile Station (STA) is traced in a building in order to transmit and receive data between mobile station and Access Point (AP), whether a patient is in an emergent situation is determined and the emergency signal is transmitted to the mobile station attached to patient, by realizing the Medical Application Radio System (called MARS below) protocol suggested by IEEE802.11 in Medical Application Radio System (called MARS below).
2. Description of the Related Art
The MARS has a function in which some medical informations occurred in a monitoring sensor of moving patient are transmitted to an office where medical doctors or nurses reside and collected data are analyzed and processed. This system consists of home position access point installed in an office, transit access point installed in a corridor or a sick room and station point.
The MARS consists of a radio LAN and wire networks, and can construct communication network using public communication network or wire LAN. The wire network provides logical service function which is necessary for communicating between networks without any period interrupting destination address management and service, and can be consisted of conventional wire LAN communication network or public communication network.
Radio LAN consists of mobile station and access point which operate in 2.400 to 2.4835 GHz (83.5 MHz) of non-license band, and the access point has a radio access function and wire LAN communication network access function being distribution system. This system can transmit and receive informations bidirectionally through mobile station, access point and wire network.
UHF telemetry systems of conventional art (400 MHz) are one-way communication system, which consist of a transmitter attached to a patient and central monitor receiver and transmit information signals about patient's situation to central monitor receiver. The system has data transmission speed of 9.6 Kbps and has dedicated network. Its operating frequency is divided every 25 KHz in the band of 406 to 512 MHz.